


Butterfly

by bestGuesses, leangreencastielmachine



Series: Baggage [1]
Category: Supernatural
Genre: Aftercare, Alternate Universe - Serial Killers, Anal, Anal Fingering, Anal Sex, BDSM, Barebacking, Blood, Blood Kink, Blow Jobs, Bottom Dean Winchester, Castiel/Dean Winchester BDSM, Choking, Coming Untouched, Consensual, Consensual Sex, Degrading kink, Dirty Talk, Foreplay, Friends With Benefits, I promise this is a serious fic, Knifeplay, M/M, Mild Blood, Orgasm Delay, Painplay, Serial Killer Castiel (Supernatural), Serial Killer Dean Winchester, Serial Killer Sam Winchester, Serial Killer Winchesters (Supernatural), Serial Killers, Shameless Smut, Slight Overstimulation, Smut, Tags Are Hard, Top Castiel (Supernatural), Top Castiel/Bottom Dean Winchester, cas plays fruit ninja with dean's body but its sexy, dean is carved like a thanksgiving turkey, fill'im up, gotta get those hits, i dont know any more carving metaphors, i dont wanna put creampie but thats going on, like a pumpkin on halloween night, nut in butt, take a shot every time i include a tag saying serial killers
Language: English
Status: Completed
Published: 2019-08-22
Updated: 2019-08-22
Packaged: 2020-09-23 17:15:02
Rating: Explicit
Warnings: Graphic Depictions Of Violence
Chapters: 1
Words: 4,029
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/20343748
Author URL: https://archiveofourown.org/users/bestGuesses/pseuds/bestGuesses, https://archiveofourown.org/users/leangreencastielmachine/pseuds/leangreencastielmachine
Summary: Dean Winchester and Castiel are friends with benefits. The catch? They're both serial killers.





	Butterfly

Dean sat down on his couch, draping a blanket over himself as he turned on the TV. He took a few deep breaths, enjoying the warmth of his home. Sam walked into the room, leaning over the couch as the news was projected onto the screen.

_ Infamous Lebanon Killer Strikes Again! _

Dean watched with amusement as they showed a mugshot. He stretched as he looked at the face on the screen.

“They didn’t do the Blue Steel one! I told them to!” Dean complained at the image. Sam rolled his eyes.

“The cops are on your ass again and you care that they didn’t use the right mugshot?” Sam scoffed as he handed Dean a cup of hot cocoa.

“I have standards, y’know,” Dean retorted before taking a sip and grinning. “Hell yeah,” he practically moaned at the taste of the drink. Sam mock gagged and plopped down on the couch next to him, a mug in his own hands.

“You been talking to Cas?” Sam asked. Dean nodded.

“We’ve been covering for each other. He showed me his go-to burial site,” Dean grinned.

“A romantic date burying dead bodies,” Sam remarked. Dean snorted.

“You know we’re straight, right?”

“Mmhmm,” Sam responded, very clearly not falling for his shit. Dean drank some more of his hot chocolate.

“How’s your week been?” Dean asked.

“Boring ass cases at work. Kills have gone smoothly, though,” he said. Dean nodded, a hint of amusement in his glance, “What?” Sam retorted.

“You work for the law, and yet you’re a killer. Jus’ find it funny,” Dean shrugged. Sam lightly kicked him.

“We all have hobbies.”

“You just have an interesting contrast there,” Dean replied.

“Cas is a goddamn _ writer _, and you’re a mechanic,” Sam said, “I think we’ve established that people you least expect are doing this.”

“Yeah yeah, guess so,” Dean said as he leaned back into the cushion, seeing a report of another murder. The victim was a tall, brunette man.

“That yours?” Dean asked.

“Not my type,” Sam responded, “Maybe Cas’.”

“They have no leads there, so if it is his, he did a good job covering his tracks.”

“Guess so,” Sam said before chugging the rest of his hot cocoa. He snatched Dean’s mug before going to clean them out, “I’m going to bed, got work in the morning.”  
  
“Sleep well, princess!” Dean teased. Sam flipped him off as he retreated into his room. Dean took a few deep breaths, looking around. There was a chill throughout his body, one he absolutely adored. He knew he wasn’t going to be able to sleep as long as he had an _ urge _, so he stood up. He changed into black clothing (easier to hide blood) before heading out to a nearby bar.

_ Hunting at the Roadhouse. Avoid it tonight _, Dean sent to Cas. Cas replied with a thumbs up, and Dean grinned. They never hit the same spot twice in one night, as that would lower the number of people that went. Not to mention that two serial killers in one bar would raise plenty of eyebrows, and the last thing that the media needed to know was that all of the local killers were working together. Dean got out of the car, heading inside and sitting down on a weathered stool. He leaned against the wooden counter as an older woman approached.

“Hey, Ellen!” He greeted with a grin.

“Hey, darlin’. You here for a late-night drink?” She asked.

“Whiskey,” he responded. She nodded, swiftly pouring him a glass before sliding it to him across the counter. He grabbed it with a thankful smile, taking a drink as he examined the crowd. A dark-haired man sat nearby, shooting him the occasional sultry glance. Dean grinned, knowing that he had found his catch for the night.

Dean was comfortable finding victims in the Roadhouse. Ellen and Jo knew what Dean did, and they always kept their mouths shut. They knew better than to talk anyway. Really, as long as nobody killed Ellen or Jo, and as long as nobody shut the Roadhouse down, Dean, Sam, and Cas were free to do as they please there. Dean even considered them to be friends.

“What brings you here?” Dean asked as he scooted over next to next to the man who had been quite clearly flirting with him. Dean looked up at him through thick lashes, spreading his legs a bit as a subtle invitation.

“Nice to have some fun sometimes. How about you, babe?” He asked.

“Sometimes it’s nice to just… let go,” Dean stated, trailing a hand up the man’s thigh and through a tear in his jeans, he squeezed his thigh lightly. He finished his drink, “So, what do ‘ya say?”

“We can go to my place,” he responded. Dean nodded with a smirk as they walked out, getting into his car. They made their way to the man’s house, a small apartment. Dean followed him inside before pinning him against the wall with a hard kiss. He gasped into it as Dean twisted a hand in his curly hair, keeping him held back, stuck securely between Dean’s body and the wall. He used his free hand to reach into his pocket, grabbing his army knife. The man didn’t even notice the blade until it was far too late.

“Sorry baby, we all let go in different ways,” Dean breathed against his lips as he buried the blade in his side. The man’s eyes widened as he froze, clearly seeming to realize what was going on. Dean twisted the knife in his body before slowly pulling it out, watching as the man fell to the floor in shock. He loved drawing it out, watching the life slowly leave his victim’s eyes. 

He loved the power. 

Dean crouched down, brushing some of the man’s hair out of his face and smearing his own warm blood over his forehead in the process. He adored how easily he could end another life. He lived for the sensation, knowing that blood was on his hands. He knew he was fucked up, but _ god _ did he love it.

“Let go, sweetheart,” he responded. The man gawked for a second before Dean grabbed his knife once more, slowly sinking it into his neck. Blood pooled right under his Adam’s apple, dripping down the sides of his neck in neat lines and staining the carpet a deep crimson. Dean watched with a soft smile as the man coughed, his eyes beginning to dull as he bled out. When Dean was sure his victim was almost gone, he pulled the knife out and buried it into his chest a few more times, basking in the rush he got. He eventually stood, bloodied and satisfied as he shut the man’s eyes. 

He observed the crimson stain of the once beige carpet, the bloodied body idle and never to move again. The wind was blowing through a window that was cracked open, blowing the curtains into the air. It was chilly, quickly drying the blood that covered Dean. Normally, that wouldn’t bother him, but dried blood was always much harder to wash off, so he figured that he could get cleaned up as fast as possible to ensure the cops wouldn’t be on his ass.

Dean glanced down at his blood-soaked hands with a dark grin, feeling mostly fulfilled. Of course, there was only one thing that could really leave Dean truly satisfied after a kill. He grabbed his phone, struggling to unlock it due to his bloody fingers. He eventually just used the microphone to send a text, having given up on fighting the finger sensors in the screen.

_ Can I come over? _He sent Cas.

_ Always. _ Cas responded. Dean grinned, getting into the car and driving to Cas’. He then got out, half jogging up the steps to his apartment before ringing the doorbell. Cas answered in pajamas, looking Dean up and down.

“Take a shower,” he ordered simply. Dean scoffed in response, although he was grinning. He walked to the bathroom, stripping and turning the shower on. He kept it cold, hoping the chill would calm his mind. It did eventually, and he watched as the blood clouded the clear water red. He eventually finished getting cleaned up, walking out just in a towel. Cas walked over, his arms crossed over his chest. He met Dean’s eye, a certain dark tinge that Dean adored.

“I’m clean now,” Dean stated. Cas nodded, stepping forward and into Dean’s space. Dean took a teasing step back, a challenging hint in his eyes as Cas cornered him. Cas placed his hands over Dean’s bare hips, pulling him in for a slow kiss.

“Look at you. Just killed someone and now you need someone to remind you that you’re just a little whore, huh?” Cas asked, curling a hand in Dean’s hair and forcing his head back. Dean smirked.

“You know you love it when I come over. C’mon, just bend me over and fuck me. I know you wanna.”

“You’re not the one giving orders here, slut. So kindly shut the fuck up unless I say you can speak,” Cas growled.

“And if I don’t wanna?”

“Then I’ll leave you here. Desperate. And you know damn well that nobody can give you what you need other than _ me _. So, learn some manners, or I’ll leave you begging.”

Dean swallowed thickly, still grinning, “I think I’ll go with option A, then.”

“Good boy,” Cas smirked, tilting his head back further before sucking and biting a mark right over his throat. Dean whined, clutching onto the front of Cas’ shirt as he attempted to pull it off. Cas made no move to help him, watching as Dean groaned in annoyance. 

“Fucker,” Dean mumbled.  


“What was that?” Cas hummed, his tone warning.

“Nothing.”

“Good. Keep your pretty little mouth shut before I shut it for you,” Cas said. Dean nodded, and Cas seemed please enough with that for an answer.

Cas continued marking Dean before pushing his body flat against Dean’s forcing him fully against the wall. Dean loved the rush, knowing damn well that Cas could snap at any second and end him? He adored it. But he did trust Cas wholeheartedly, and while he knew that Cas _ wouldn’t _, knowing he was capable of it was exhilarating. Cas nipped at his earlobe.

“_ Mine _,” he growled possessively. Dean nodded.

“Yours,” he replied, practically gasping. Cas gave a pleased smile, although it was dark and hungry.

“On your knees,” he ordered.

“And what if I don’t want to?” Dean asked, challenge in his tone.

“Are you the one giving orders here?”

“I don’t have to be.”

“I don’t fucking _ care _,” Cas retorted, wrapping his hand around Dean’s neck. He pressed down, cutting off Dean’s airflow. Dean still gave Cas a challenging look as Cas moved, grinding their cocks together. Dean threw his head back.

“You’re my little bitch. You do what I say, slut,” Cas said against Dean’s lips, letting go of his neck and allowing him to breathe. Dean nodded, unwrapping the towel from where it was wrapped around his hips. Cas chuckled darkly.

“Need me that bad? That much of a slut for my cock? You’ve been here for the past 4 nights, Dean.” Dean nodded desperately in reply. Cas shoved him to his knees, grinning as Dean kneeled and looked up at him. Cas pulled his pajama pants down, running a hand over his clothed cock. Dean tried to move forward to mouth at him through his underwear, but Cas pushed him back by the head.

“You’re gonna have to wait,” Cas growled. Dean took a deep breath through his nose before nodding, continuing to stroke himself through his briefs. Dean watched, keeping his hands on his own knees. Cas finally pulled his underwear down, slowly stroking his hard cock. Dean looked up at him.

“Please, sir. I wanna taste you,” he said.

“Then do it,” Cas said. Dean immediately took Cas into his mouth, grabbing his thighs desperately. Cas curled a hand in Dean’s hair, watching as Dean got used to the stretch in the corners of his lips.

“Want me to use you like the whore you are? Fuck your mouth until you’re choking?” Dean nodded as Cas gave a low chuckle. He curled his hand in Dean’s hair, pushing his cock as far down Dean’s throat as he could. Dean coughed for a moment, and he pulled out to make sure that he was still fine. As soon as he was sure Dean was okay, he went back to fucking Dean’s mouth, watching as Dean shut his eyes and leaned forward to deepthroat him. He grabbed Cas’ thighs harder as Cas grinned, pushing him against the wall and grinning as Dean relaxed, taking it. Cas stayed there for a while before pulling out, tapping the bottom of Dean’s chin.

“You’re so well trained. Taking my entire cock down your throat. You’re a good little bitch,” he chuckled before immediately speaking, “Stand,” he ordered. His tone was almost nonchalant, but Dean clearly reacted. He scrambled to his feet, just close enough to be trapped between Cas’ body and the wall. He resisted the urge to touch himself as Cas leaned in, pressing their cocks together and wrapping his hand around both of them, stroking slowly. He knew Dean had no lubrication, so he made sure not to be too rough. Dean leaned back against the wall, bucking his hips up. Cas laughed.

“Poor baby, already so needy,” Cas remarked, “Kneel on the bed.”

Dean wasted no time, moving over and getting on his knees, resting his arms on the headboard as he pushed his hips out and towards Cas. Cas grabbed the lube, slicking a finger up before stalking over to Dean, running a hand over his ass with a grin, delivering a solid spank just to watch him gasp. He ran a finger over his hole, watching as Dean tried to push back against him. Cas laughed in response, moving his finger away as Dean let out a choked noise, already whining and begging. It was a long while of Dean pleading needily before Cas finally pushed his finger inside. Dean immediately gave a blissful moan as he tried his best to fuck himself back on Cas’ finger. Cas ran his other hand down Dean’s arched back, snaking his hand down to Dean’s thigh and squeezing. He laughed as Dean gave pathetic, desperate whimpers.

“Cas, please-” He practically sobbed.

“Please, what?” He asked leaning over before curling his fingers in Dean’s hair, yanking his head back, “Need to be a slut? Not enough for you?” He asked. Dean nodded as Cas grinned, adding his middle finger in as he began to relentlessly rub against his prostate, watching as Dean gripped the headboard with white knuckles.

“_ Castiel _!” he practically screamed, drawing out every syllable as he ducked his head with a wrecked moan. Cas grinned.

“God, you’re such a needy little whore,” He chuckled, working another finger inside of him along with the first two. Dean’s jaw hung slack as he worked his hips back onto Cas’ knuckles, trying to take as much as he could. Cas watched with lidded eyes, palming himself as Dean used his fingers.

“More- please, Cas,” he whined, his tone desperate, “I need you- I need you _ so _ damn bad,” he choked out.

“What do you need, then?” Cas asked, slamming his fingers into Dean’s prostate to watch him arch his back with a sharp gasp.

“I- I need you to use me,” he managed to choke out, “Need you in me. Please-”

“How do you want me to use you, baby? Want me to do whatever I want to you?” Cas purred, tracing light fingertips over the skin on Dean’s side, trailing down to his thigh before squeezing tightly, “Want me to make you _ mine _?”

“I’m already yours, sir,” Dean breathed as Cas responded with a low chuckle.

“You don’t have much to show for it. And I don’t like to share,” Cas gently dug his nails into the flesh of Dean’s thigh, “I think you need something to show that you belong to _ me _.”

“Like what?” He asked quietly. Cas smirked, stepping aside before returning with a blade. From the glance Dean got of it, it was some sort of butterfly knife with a neatly curved blade. He knew what Cas was going to do, but he trusted him implicitly. Dean had no concerns with what Cas was going to do with him.

“You ready, baby?” Cas asked, tracing the cool metal over Dean’s back and ass. Dean nodded as Cas grinned, slowly sinking the blade into Dean’s skin, drawing a shallow, thin red line. Blood beaded over the cut as Cas pulled the knife away. Dean stayed still the entire time, taking a few slow breaths. It stung, but that only seemed to edge him on further. He knew Cas would leave scars if he let him, and truth be told, Dean _ wanted _ those marks.

“I can take it,” Dean said when Cas sat back to examine his work. 

“I know.”

“So why are you stopping?”

“Because I want to,” Cas stated matter of factly, “Do you want me to continue? Wanna be carved up?” he asked with a grin. Dean nodded.

“Want everyone to know that I’m yours,” Dean said.

“Good,” Cas said before the knife was digging in his flesh, slicing over his back. Without much of a break, Cas started another cut right over his ass, watching the blood trickle down Dean’s trembling thighs. Dean was shaking, tears forming in the corners of his eyes from the pain. After a few more neat slices, Cas paused to let Dean compose himself. He was still shaking, panting a bit.

“Do you need me to stop, Dean?” Cas asked, a small amount of genuine concern in his tone.

“Did I say I wanted you to?”

Cas curled a hand in Dean’s hair, yanking him up harshly, “Don’t sass me, _ brat _. I’m the one with the knife here.”

Dean rolled his eyes in response, “So why aren’t you using it?”

“I’ll use it when I wanna use it, Dean. You don’t get a choice here,” he growled before letting go of Dean’s hair, dropping him and watching the way he twitched and whimpered. Cas chuckled lowly, running a hand over his back and making sure to avoid the cuts as he moved back to run the pad of his thumb over Dean’s hole. Dean whined, bucking his hips back a bit as Cas sliced his thigh in warning.

“Goddammit, jus’ fuck me already!” Dean huffed. Cas slowly sunk the blade into Dean’s back, not enough to cause damage _ too _ serious, but enough to serve as a warning.

“Shut the hell up. I don’t care what you want here, slut. I’ll gag you if I need to.”

Dean shot him a glare, “You know I hate the gag,” he said, although it wasn’t really the truth. A small part of him wanted to be gagged.

“And you know that I don’t give a single shit,” Cas responded as he grabbed the bottle of lube, slicking himself up. Dean opened his mouth to object as Cas finally slammed in, his words cut off in a choked moan as he gripped the bed sheets. A bit of blood smeared on Cas’ hips, but neither of them seemed to care as Cas slowly ran a hand over Dean’s thigh.

“Are you ready for me to move?” Cas asked.

“_ Please _,” Dean gasped, ducking his head as Cas smirked. Cas slowly rocked his hips, allowing Dean some time to adjust. He knew Dean enjoyed the pain, but it was for the best that he was comfortable in that moment. When Dean began to move with him, he sped up, making small gasping noises as his hips met the flesh of Dean’s ass.

“_ Cas, _” Dean whined as he threw his head back, panting as his thighs trembled. 

“Is this what you wanted, whore? A good pounding?” Cas replied as he sped up, his own breaths uneven. Dean nodded with a low moan, adjusting his hips and arching his back when Cas hit his prostate. 

“Yes, sir-” Dean almost screamed. Cas placed a hand on Dean’s waist as he fucked him harder, grinning at Dean’s moans.

“God, you’re such a good little bitch,” Cas panted, “You take my cock so well,” He chuckled, placing a firm spank to Dean’s ass. Dean made a choked off noise, his knuckles white from how tightly he was gripping the bed sheets. He was already covered in a thin sheen of sweat, gasping and whimpering as he tried desperately to stay quiet.

“‘m close,” Dean whined, arching back against Cas.

“Too bad,” Cas chuckled, “You can’t cum until I say you can.”

“Cas,” Dean whined before Cas hit his prostate hard, leaving him a screaming mess. Cas only seemed to speed up, biting his lip as he made sure Dean wasn’t touching himself. He knew he had Dean well trained and that he wouldn’t, but it never hurt to be sure. The knife was long discarded on the sheets next to Dean’s knee, staining the white fabric a dark red. Cas grinned, blood still covering Dean’s thighs and back from his cuts.

“Gonna cum untouched for me? Only on my cock?” He asked as Dean nodded, “Then do it.” Dean made a low whining sound, and it only took a few more well placed thrusts before he was spilling over the sheets with a scream, barely holding himself up as he trembled. Cas didn’t slow down the entire time, even after Dean began to whine from the pleasure beginning to become overstimulating.

“Need you to fill me up,” Dean breathed, still shaking. Cas nodded.

“Already came and you still want more? You’re insatiable,” he laughed before speeding up, fucking him hard until he finished. Cas held Dean up as he came inside of him, watching as Dean’s eyes shut and he moaned. When Cas pulled out and let go of Dean, he fell limp against the sheets. Cas grabbed a rag, cleaning himself up before pulling his pants up. He walked over, running a gentle hand through his hair.

“You awake, baby?” Cas asked softly. Dean nodded groggily, clearly out of it. Cas leaned over, gently kissing him on the forehead before beginning to clean Dean up. After quite a few bloodied rags, Cas wrapped his wounds and gently traced his fingers over Dean’s skin. He got some underwear on him before gently lifting him and setting him down on a nearby cushioned chair. Dean had a small grin on his face, mostly limp as he slumped over in the chair with his eyes shut.

“I’m gonna get you some water, okay?” Cas asked.

“Yeah,” Dean mumbled as Cas nodded, quickly retreating and returning with a bottle. He placed it to Dean’s lips, letting him drink a bit before capping it and setting it aside.

“I’m gonna change the sheets and then you can sleep,” he said. Dean hummed in affirmation before Cas went to clean up, putting the knife and lube away before switching the sheets and throwing the dirty ones in the washer. He added some peroxide to get the blood off. Cas then picked Dean up and laid him down, sitting next to him.

“How do you feel?” Cas asked gently, “Was that too much?”

Dean shook his head, “It was good,” he responded groggily, “I’m tired.”

“I can tell,” Cas chuckled, “Do you feel dizzy? Nauseous?”

Dean nodded, “Dizzy.”

“Do you think you can drink some juice for me?”

“Yeah,” he mumbled sleepily. Cas ran a gentle hand through his hair before heading to the kitchen, getting Dean a glass of apple juice and getting him to finish that.

“Tomorrow morning, I’m gonna check on you and get you an actual bath, okay? If you still feel sick, then I’ll be here to take care of you.”

“Thank you, Cas,” Dean responded gratefully.

“Of course. Sleep well.”

“I will, sir,” he said cheekily before closing his eyes and drifting off. 


End file.
